If you didn't, have to enter in the west door, opposite the Murge, and activate the machinery. There are some puzzles there, then you need to go back to the cistern and pull the lever. there's an other little puzzle then, but i'll let to you :) You've alredy almost found...

If you didn't, have to enter in the west door, opposite the Murge, and activate the machinery. There are some puzzles there, then you need to go back to the cistern and pull the lever. there's an other little puzzle then, but i'll let to you :) You've alredy almost found...

Well I've done everything in cistern where you have to move those valves, but that's abou it, i couldn't find anything because the lack of light